The present invention relates to plural component dispensing systems, and more particularly to a mixing module for a plural component dispensing system.
Typically, a plural component dispensing system uses a resin component which is chemically inert in its isolated form, and an isocyanate catalyst material which is also chemically inert in its isolated form. When the catalyst and the resin are combined, an immediate chemical reaction begins taking place that results in the cross-linking, curing, and solidification of the mixture. As the chemical reaction takes place, but before it has progressed too far, the mixed material can be dispensed or sprayed into its intended form and/or position. Such a plural component dispensing system can be used to spray paint onto an article.
Due to the chemical reaction between the resin and the catalyst, the two components are stored separately and mixed in specific proportions immediately in time prior to use. The mixing traditionally has occurred adjacent to where the components are stored, which can be a substantial distance from where the mixture is dispensed. This is especially true in the case of a spray paint booth where the components are stored outside of the booth and the paint application occurs inside the booth. In such an arrangement, the mixed paint may have to travel 50 feet prior to being sprayed.
When dispensing of the mixture is suspended or completed or when the mixture must be changed (e.g., to create a different paint color), the material that is already mixed must be flushed from the dispensing system using a solvent. The flushed mixture is generally discarded, creating waste, and the solvent is generally not reused, creating more waste. Also, the flushing process takes time to complete, which occupies the dispensing system and prevents it from being used productively.